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1.
Int J Surg Pathol ; 32(2): 374-379, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-37248556

RESUMO

Malignant gastrointestinal neuroectodermal tumor (GNET), also referred to as clear cell sarcoma-like tumor of the GI tract is a rare mesenchymal tumor of the gastrointestinal tract. It has to be distinguished from various mimickers including gastrointestinal stromal tumor (GIST) due to its aggressive course and different natural history and therapeutic approach. Here we report a case of GNET arising in the small intestine with aberrant DOG1 expression posing a diagnostic challenge. In this context, the combination of clinical, histomorphological, immunohistochemical, and molecular features helped to establish a proper diagnosis.


Assuntos
Neoplasias Gastrointestinais , Tumores do Estroma Gastrointestinal , Neoplasias de Tecido Conjuntivo e de Tecidos Moles , Humanos , Neoplasias Gastrointestinais/diagnóstico , Neoplasias Gastrointestinais/cirurgia , Intestino Delgado/cirurgia , Tumores do Estroma Gastrointestinal/diagnóstico
2.
Clin Pharmacol Drug Dev ; 12(10): 956-965, 2023 10.
Artigo em Inglês | MEDLINE | ID: mdl-37587797

RESUMO

Deucravacitinib is an oral, selective, allosteric inhibitor of tyrosine kinase 2, an intracellular signaling kinase involved in the pathogenesis of immune-mediated inflammatory diseases. The absolute and relative bioavailability (BA) were evaluated in phase 1, open-label studies in healthy adults to assess (1) the absolute BA of the deucravacitinib tablet formulation following single oral administration of a 12-mg tablet and an intravenous microdose infusion of 0.1-mg carbon-13 and nitrogen-15-labeled deucravacitinib ([13 C2 , 15 N3 ] deucravacitinib) solution in 8 subjects, and (2) the relative oral BA of deucravacitinib tablet and capsule formulations at the 3- and 12-mg dose levels in 20 subjects. The absolute oral availability of deucravacitinib in the tablet formulation was near complete at approximately 99%. The total clearance (254 mL/min) was low relative to hepatic blood flow, and volume of distribution (∼140 L) was greater than total body water, indicating extravascular distribution. Deucravacitinib systemic exposure (maximum plasma concentration, area under the plasma drug concentration curve from time zero to the time of the last quantifiable nonzero concentration, and area under the plasma drug concentration-time curve from time zero extrapolated to infinity) after administration of the tablet formulation were similar to the capsule at the tested 3- and 12-mg doses. In both studies, deucravacitinib was safe with no clinically relevant changes in laboratory values, electrocardiogram parameters, or vital signs.


Assuntos
Disponibilidade Biológica , Adulto , Humanos , Infusões Intravenosas , Administração Oral , Comprimidos
3.
BMJ Open ; 13(6): e070500, 2023 06 22.
Artigo em Inglês | MEDLINE | ID: mdl-37349096

RESUMO

OBJECTIVES: To describe the implementation of screening for cryptococcal antigenaemia by point-of-care (POC) serum cryptococcal antigen (CrAg) lateral flow assay, measure the prevalence and factors associated with serum cryptococcal antigenaemia in the routine programmatic setting. DESIGN: Cross-sectional study. SETTING: Seventeen publicly funded antiretroviral therapy (ART) centres in Mumbai, India. PARTICIPANTS: Serum CrAg screening was offered to all adolescents (>10 years of age) and adults with advanced HIV disease (AHD) (CD4 <200 cells/mm3 or with WHO clinical stage III/IV) regardless of symptoms of cryptococcal meningitis. PRIMARY AND SECONDARY OUTCOME MEASURES: The primary outcome was to describe the implementation of serum CrAg screening and secondary outcome was to measure the prevalence of serum cryptococcal antigenaemia and its risk factors. RESULTS: A total of 2715 patients with AHD were tested for serum CrAg by POC assay. Of these, 25 (0.9%) had a CrAg positive result. Among CrAg-positive patients, only one had symptoms. Serum CrAg positivity was 3.6% (6/169) and 1.6% (6/520) among those presenting with CD4 <100 cells/mm3 in the treatment naïve and treatment experienced group, respectively. On multivariable analysis, CD4 count <100 cells/mm3 (OR: 2.3, 95% CI 1.01 to 5.3; p=0.05) and people living with HIV who were treatment naïve (OR: 2.5, 95% CI 1.04 to 6.0; p=0.04) were significantly associated with a positive serum CrAg result. Lumbar puncture was obtained in 20/25 patients within 4 days (range: 1-4 days) of positive serum CrAg result and one person was confirmed to have meningitis. All serum CrAg-positive patients who had a negative cerebrospinal fluid CrAg were offered pre-emptive therapy. CONCLUSIONS: Implementation of a POC CrAg assay was possible with existing ART centre staff. Initiation of pre-emptive therapy and management of cryptococcal antigenaemia are operationally feasible at ART centres. The Indian National AIDS Control Programme may consider reflexive CrAg screening of all AHD patients with CD4 <100 cells/mm3.


Assuntos
Cryptococcus , Infecções por HIV , Adulto , Adolescente , Humanos , Prevalência , Estudos Transversais , Infecções por HIV/complicações , Infecções por HIV/epidemiologia , Infecções por HIV/tratamento farmacológico , Testes Imediatos , Antígenos de Fungos/análise , Índia/epidemiologia , Contagem de Linfócito CD4
4.
PLoS One ; 18(4): e0284602, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37115735

RESUMO

BACKGROUND: It is important to understand the current internet-related sexual behaviours of high-risk groups such as men who have sex with men (MSM). We designed the present study to understand the types of online/mobile apps used by MSM and male-to-female transgendered people/hijras [TGH] in Mumbai, India. We also compared the internet-related 'partner seeking' and 'sexual behaviours' in MSM and TGH in Mumbai, India. METHODS: This is a cross-sectional analysis of secondary data collected (April to June 2020) from 8582 MSM and 4163 TGH from five targeted intervention programmes each in Mumbai, Maharashtra, India. Data on demographics, years of association with the intervention, number and type of online/mobile apps used, sexual behaviours including partners from virtual space and non-virtual (physical) space, group sex, attending parties, mobility for sexual partners, and HIV status were collected. RESULTS: MSM were more likely to have mobile phone (88% vs 51%, p < 0.001) and internet access over the phone (78% vs 27%; p < 0.001) compared with TGH. The common apps used by MSM were Grindr (48%), Facebook (42%), and Blued (36%). MSM were more likely to have partners from virtual space (91% vs 67%; p < 0.001). A higher proportion of MSM had attended parties (28% vs 2%; p < 0.001), had group sex (16% vs 6%; p < 0.001), and were mobile for sex (25% vs 4%). MSM and TGH who had partners from virtual space were significantly more likely to report 'missed a condom at least once during penetrative sex in the past one week' (17% vs 12%; p<0.001). In HIV positive MSM, group sex, parties, and mobility for sex, were only in those who reported partners from the virtual space. CONCLUSIONS: Internet-based interventions for MSM should be incorporated in the existing targeted intervention programme and outreach workers should be trained in virtual outreach services. Among TGH, given the low reach and use of smartphones and apps, internet-based interventions may not be such a useful option, and the existing physical targeted intervention programmes should be strengthened.


Assuntos
Infecções por HIV , Minorias Sexuais e de Gênero , Humanos , Masculino , Feminino , Homossexualidade Masculina , Infecções por HIV/epidemiologia , Infecções por HIV/prevenção & controle , Estudos Transversais , Assunção de Riscos , Índia , Comportamento Sexual , Parceiros Sexuais
5.
PLoS One ; 17(9): e0273970, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36103506

RESUMO

BACKGROUND: People with Advanced HIV Disease (AHD) are at higher risk of TB coinfection and mortality. However, there are challenges in TB diagnosis with the currently recommended diagnostic tools. WHO recommends lateral flow urine lipoarabinomannan (LF-LAM) assay to assist TB diagnosis among AHD patients. We assessed the utility and acceptability of using urine LF-LAM assay for TB diagnosis among patients at public Antiretroviral Therapy (ART) Centres in Mumbai. METHODS: The cross-sectional study was conducted among adult AHD patients accessing care from 17 ART centres during November,2020-June, 2021. Urine LF-LAM was offered as routine care for eligible patients in combination with standard diagnostic tests. We calculated the proportion of positive LF-LAM results by CD4 categories and TB symptoms and performed multivariable logistic regression to determine the factors associated with LF-LAM positivity. RESULTS: Among 2,390 patients, the majority (74.5%) had CD4 between 101-200 cells/mm3. The mean age was 43.7 years (SD:10.6), 68.6% were male, 8.4% had TB symptoms and 88.0% were on ART. The overall proportion of patients with urine LF-LAM positive results was 6.4%. Among PLHIV with CD4≤100 cells/mm3, the positivity was 43.0% and 7.7% in symptomatic and asymptomatic patients, respectively. Among PLHIV with a CD4>100 cells/mm3, the positivity was 26.7% and 2.7% in symptomatic and asymptomatic patients respectively. Urine LF-LAM positivity was higher among inpatients, ART naïve, patients on treatment for <6 months, symptomatic and in WHO clinical stage III/IV of HIV disease as compared to the reference categories. We detected an additional 131 TB cases with urine LF-LAM in combination with the standard diagnostic tests. CONCLUSION: The study demonstrated the utility of urine LF-LAM for TB diagnosis among AHD patients and the simple, user-friendly test was acceptable as part of routine care. Inclusion of urine LF-LAM test in the current diagnostic algorithm may facilitate early TB diagnosis among AHD patients.


Assuntos
Infecções por HIV , Tuberculose , Adulto , Estudos Transversais , Feminino , Infecções por HIV/complicações , Infecções por HIV/tratamento farmacológico , Humanos , Índia/epidemiologia , Lipopolissacarídeos , Masculino , Sensibilidade e Especificidade , Tuberculose/complicações , Tuberculose/diagnóstico , Tuberculose/epidemiologia
6.
J Glob Oncol ; 4: 1-12, 2018 09.
Artigo em Inglês | MEDLINE | ID: mdl-30222028

RESUMO

Purpose Limited data exist on intensifying chemotherapy regimens in the treatment of adult acute lymphoblastic leukemia (ALL) outside the setting of a clinical trial. Materials and Methods Retrospectively, data from 507 consecutive adults (age ≥ 15 years) with a diagnosis of ALL treated at our center were analyzed. Standard-risk (SR) patients were offered treatment with a modified German Multicenter ALL (GMALL) regimen, whereas high-risk (HR) patients were offered intensification of therapy with hyperfractionated cyclophosphamide, vincristine, doxorubicin, and dexamethasone (HCVAD). Because of resource constraints, a proportion of HR patients opted to receive the same treatment regimen as used for SR patients. Results There were 344 SR patients (67.8%) and 163 HR patients (32.2%) at diagnosis. Among the HR patients, 53 (32.5%) opted to receive intensification with the HCVAD regimen. The SR cohort showed a superior 5-year event-free survival rate compared with the HR cohort (47.3% v 23.6%, respectively; P < .001). Within the HR subgroup, there was no statistically significant difference in overall survival or event-free survival between patients who received the modified GMALL regimen (n = 59) and patients who received HCVAD (n = 53). Conclusion Intensified therapy in the HR subset was associated with a significant increase in early treatment-related mortality and cost of treatment. A modified GMALL regimen was found to be cost-effective with clinical outcomes comparable to those achieved with more intensive regimens.


Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Leucemia-Linfoma Linfoblástico de Células Precursoras/tratamento farmacológico , Adolescente , Adulto , Idoso , Protocolos de Quimioterapia Combinada Antineoplásica/economia , Ciclofosfamida/uso terapêutico , Países em Desenvolvimento , Dexametasona/uso terapêutico , Doxorrubicina/uso terapêutico , Feminino , Humanos , Índia , Estimativa de Kaplan-Meier , Masculino , Pessoa de Meia-Idade , Leucemia-Linfoma Linfoblástico de Células Precursoras/economia , Leucemia-Linfoma Linfoblástico de Células Precursoras/genética , Estudos Retrospectivos , Resultado do Tratamento , Vincristina/uso terapêutico , Adulto Jovem
7.
Biol Open ; 6(1): 100-108, 2017 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-28089995

RESUMO

Low efficiency of somatic cell reprogramming and heterogeneity among human induced pluripotent stem cells (hiPSCs) demand extensive characterization of isolated clones before their use in downstream applications. By monitoring human fibroblasts undergoing reprogramming for their morphological changes and expression of fibroblast (CD13), pluripotency markers (SSEA-4 and TRA-1-60) and a retrovirally expressed red fluorescent protein (RV-RFP), we compared the efficiency of these features to identify bona fide hiPSC colonies. The co-expression kinetics of fibroblast and pluripotency markers in the cells being reprogrammed and the emerging colonies revealed the heterogeneity within SSEA-4+ and TRA-1-60+ cells, and the inadequacy of these commonly used pluripotency markers for the identification of bona fide hiPSC colonies. The characteristic morphological changes in the emerging hiPSC colonies derived from fibroblasts expressing RV-RFP showed a good correlation between hiPSC morphology acquisition and silencing of RV-RFP and facilitated the easy identification of hiPSCs. The kinetics of retroviral silencing and pluripotency marker expression in emerging colonies suggested that combining both these markers could demarcate the stages of reprogramming with better precision than with pluripotency markers alone. Our results clearly demonstrate that the pluripotency markers that are routinely analyzed for the characterization of established iPSC colonies are not suitable for the isolation of pluripotent cells in the early stages of reprogramming, and silencing of retrovirally expressed reporter genes helps in the identification of colonies that have attained a pluripotent state and the morphology of human embryonic stem cells (hESCs).

8.
Indian J Pediatr ; 83(8): 799-804, 2016 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-26924654

RESUMO

OBJECTIVE: To describe clinical and flow cytometric immunophenotyping details of 26 patients of Leukocyte adhesion deficiency-I (LAD-I) along with molecular characterization of 7 patients. METHODS: Diagnosis of LAD-I was suspected on the basis of clinical features, white blood cell count and absolute neutrophil counts and flow cytometric assessment of expression of CD18 and CD11(a, b, c) on leukocytes. Mutation analysis was performed using DNA PCR and conformation sensitive gel electrophoresis (CSGE) technique followed by sequencing. RESULTS: All the patients were symptomatic by the age of 6 mo, with history of recurrent bacterial infections involving skin, mucosa or umbilical cord (omphalitis) being the most frequent presenting symptoms. White blood cells (WBC) and absolute neutrophil counts (ANC) were markedly elevated, without any specific morphological findings. On flow cytometry, CD11a and CD11c showed moderate correlation with CD18 expression. Mutation analysis was performed in 7 patients and six different mutations (4 missense, 2 nonsense and 1 splice site) were identified, all of which were homozygous in nature. CONCLUSIONS: A presentation of repeated bacterial infections during infancy, especially omphalitis, with markedly elevated absolute neutrophil counts should trigger investigations for LAD-I including flow cytometric analysis of CD11/CD18 expression.


Assuntos
Antígenos CD18 , Análise Mutacional de DNA , Síndrome da Aderência Leucocítica Deficitária , Infecções Bacterianas , Pré-Escolar , Homozigoto , Humanos , Índia , Lactente , Síndrome da Aderência Leucocítica Deficitária/diagnóstico , Síndrome da Aderência Leucocítica Deficitária/genética , Síndrome da Aderência Leucocítica Deficitária/imunologia , Leucócitos
10.
Hemoglobin ; 39(6): 415-8, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26365411

RESUMO

α-Thalassemia (α-thal) is characterized by large deletions involving the variable regions of α2 and/or α1 genes. Nondeletional mutations and polyadenylation (polyA) signal sequence motif mutations are less common. In this retrospective study, we describe a fragment length analysis-based polymerase chain reaction (PCR) assay for screening the T(Indian) (AATAAA > AATA- -; HBA2: c.*93_*94delAA) polyA signal deletion along with its clinical and laboratory presentation in 21 patients. Most of the patients were diagnosed in early adulthood with a clinical presentation ranging from asymptomatic in the heterozygous state to severe Hb H disease with a prominent hemolytic component in the homozygous state. On genetic analysis, 14 patients were found to be homozygotes, five were compound heterozygotes and two were heterozygotes. Thus, the T(Indian) polyA signal deletion is common in the Indian population and should be screened for in patients with nondeletional α-thal mutations.


Assuntos
Regiões 3' não Traduzidas , Poli A , Deleção de Sequência , alfa-Globinas/genética , Talassemia alfa/diagnóstico , Talassemia alfa/genética , Análise Mutacional de DNA , Índices de Eritrócitos , Feminino , Heterozigoto , Homozigoto , Humanos , Índia/epidemiologia , Masculino , Fenótipo , Vigilância da População , Talassemia alfa/epidemiologia
11.
Org Lett ; 17(1): 14-7, 2015 Jan 02.
Artigo em Inglês | MEDLINE | ID: mdl-25522212

RESUMO

An efficient, stereoselective synthesis of 4'-Ed4T is demonstrated. The synthesis is highlighted by a regioselective TMSOTf-mediated acetal opening, a Claisen rearrangement to set the key 4'-stereocenter as well as the olefin, and a one-pot nonaflation/elimination to deliver the alkyne moiety. The synthesis proceeds in eight steps from 5-methyluridine and occurs in 37% overall yield.


Assuntos
Estavudina/análogos & derivados , Uridina/análogos & derivados , Alcenos/química , Alcinos/química , Estrutura Molecular , Estavudina/síntese química , Estavudina/química , Estereoisomerismo , Uridina/síntese química , Uridina/química
12.
Leuk Lymphoma ; 56(2): 420-5, 2015 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-24828863

RESUMO

In a first series from India, we report 32 cases of lymphoplasmacytic lymphoma/Waldenström macroglobulinemia (LPL/WM) over 7 years. Here, we analyzed 32 patients with LPL/WM for MYD88 L265P mutation and correlated mutation staus with hematological and biochemical parameters and also with the International Prognostic Scoring System (ISSWM) and treatment response. Twenty-seven out of 32 cases of LPL/WM (84.3%) harbored the MYD88 L265P mutation. MYD88 wild-type WM was associated with a lower number of tumor cells (p<0.01) and older age (p=0.02) and a lower ISSWM score at presentation (p=0.03) as compared to mutated LPL/WM. On evaluation of response (n=23), 44.4% of patients with MYD88 mutated LPL/WM had progressive disease, whereas no patient in the MYD88 unmutated group changed their baseline status. We confirm the high frequency of MYD88 mutations in LPL/WM. Although the number of MYD88 wild-type cases was limited, our data indicate that MYD88 may represent an adverse prognostic marker for LPL/WM.


Assuntos
Mutação de Sentido Incorreto , Fator 88 de Diferenciação Mieloide/genética , Macroglobulinemia de Waldenstrom/genética , Macroglobulinemia de Waldenstrom/patologia , Idoso , Sequência de Bases , Biomarcadores Tumorais/genética , Análise Mutacional de DNA , Progressão da Doença , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Dados de Sequência Molecular , Prognóstico , Indução de Remissão , Estudos Retrospectivos , Resultado do Tratamento , Macroglobulinemia de Waldenstrom/tratamento farmacológico
13.
Pediatr Ann ; 43(2): e28-32, 2014 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-24512158

RESUMO

Imagine an environment where health care coordination is seamless; where the pediatricians and their care teams could significantly reduce the time it takes to communicate and transfer the information between physicians, patients, and their families. Imagine a situation where unnecessary referrals and investigations are avoided, saving costs and anxieties for the patients. Welcome to the world of telemedicine and a patient-centered medical home (PCMH). Comprehensive health care delivered in the most efficient manner with the least expense is the cornerstone of these concepts. The concept of PCMH was first introduced in 1967 by the American Academy of Pediatrics (AAP) Council on Pediatric Practice in the book, Standards of Child Health Care. The medical home concept originally referred to one central source of medical records for children with special health care needs. During the past 4 decades, this concept has transformed beyond data entry to methods of delivering the best quality of care for all children. In 2007, a joint statement by the AAP, the American Academy of Family Physicians, the American College of Physicians, and the American Osteopathic Association endorsed the PCMH concept.


Assuntos
Assistência Centrada no Paciente , Pediatria , Telemedicina , Criança , Humanos , Assistência Centrada no Paciente/economia , Qualidade da Assistência à Saúde , Telemedicina/economia , Estados Unidos
14.
Head Neck Pathol ; 5(2): 180-3, 2011 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-21240573

RESUMO

Malignancy in a setting of hyaline vascular type of Castleman's disease (HVCD) is an exceptional occurrence. Herein, we report an extremely rare case of synchronous unicentric cervical HVCD and squamous cell carcinoma (SCC) of tongue mimicking stage IV disease. A 32-year-old gentleman presented with an ulcerated mass on the right tongue border and ipsilateral cervical nodal mass. As the clinical stage was IVB (T(1)N(3)M(0)), an anterior two-third glossectomy with bilateral modified neck dissection was performed. On gross examination, an ulcerated mass on the right lateral border was identified. In addition, an 8 cm large nodal mass at right level III-V was seen. Microscopy from the ulcerated growth in the tongue revealed an invasive well differentiated squamous cell carcinoma. However, the right cervical nodal mass yielded surprise histology of Castleman's disease, hyaline-vascular type. Final tumor pathological staging was revised to pT1N0M0 . This case reveals that HVCD can rarely be associated with an epithelial malignancy wherein it can clinically mimic nodal metastasis. Whether such a phenomenon occurs due to underlying immune aberrations or is a rare co-incidence remains unclear.


Assuntos
Carcinoma de Células Escamosas/diagnóstico , Hiperplasia do Linfonodo Gigante/patologia , Neoplasias da Língua/diagnóstico , Adulto , Carcinoma de Células Escamosas/complicações , Carcinoma de Células Escamosas/secundário , Hiperplasia do Linfonodo Gigante/complicações , Diagnóstico Diferencial , Humanos , Linfonodos/patologia , Metástase Linfática/diagnóstico , Masculino , Pescoço , Estadiamento de Neoplasias , Neoplasias da Língua/complicações
15.
J Ind Microbiol Biotechnol ; 35(8): 901-6, 2008 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-18496722

RESUMO

Microbial hydroxylation of o-bromophenylacetic acid provided 2-bromo-5-hydroxyphenylacetic acid. This enabled a route to the key intermediate 4-bromo-2,3-dihydrobenzofuran for synthesizing a melatonin receptor agonist and sodium hydrogen exchange compounds. Pd-mediated coupling reactions of 4-bromo-2,3-dihydrobenzofuran provided easy access to the 4-substituted-2,3-dihydrobenzofurans.


Assuntos
Aspergillus/metabolismo , Benzofuranos/metabolismo , Fenilacetatos/metabolismo , Biotransformação , Hidroxilação , Estrutura Molecular
16.
J Med Chem ; 51(5): 1145-9, 2008 Mar 13.
Artigo em Inglês | MEDLINE | ID: mdl-18260618

RESUMO

The C-aryl glucoside 6 (dapagliflozin) was identified as a potent and selective hSGLT2 inhibitor which reduced blood glucose levels in a dose-dependent manner by as much as 55% in hyperglycemic streptozotocin (STZ) rats. These findings, combined with a favorable ADME profile, have prompted clinical evaluation of dapagliflozin for the treatment of type 2 diabetes.


Assuntos
Diabetes Mellitus Tipo 2/tratamento farmacológico , Glucosídeos/síntese química , Hipoglicemiantes/síntese química , Rim/metabolismo , Inibidores do Transportador 2 de Sódio-Glicose , Administração Oral , Animais , Compostos Benzidrílicos , Glicemia/metabolismo , Diabetes Mellitus Experimental/tratamento farmacológico , Glucosídeos/química , Glucosídeos/farmacologia , Humanos , Hipoglicemiantes/química , Hipoglicemiantes/farmacologia , Ratos , Transportador 2 de Glucose-Sódio , Estereoisomerismo
17.
J Org Chem ; 72(25): 9746-9, 2007 Dec 07.
Artigo em Inglês | MEDLINE | ID: mdl-17997568

RESUMO

An efficient and practical process to generate beta-C-arylglucoside derivatives was achieved. The process described involves Lewis acid mediated ionic reduction of a peracetylated 1-C-aryl methyl glucoside derived from the addition of an aryl-Li to selectively protected delta-D-gluconolactone. The reduction of the 2-acetoxy-1-C-oxacarbenium ion intermediates proceeds with a high degree of selectivity to give beta-C-arylglucosides without 2-acetoxy group participation. Furthermore, during the reduction process we also identified an unprecedented critical role of water. By changing from the usual benzyl ether protecting groups because of cost and chemical compatibility concerns, the new process is made additionally efficient and highly selective.


Assuntos
Glucosídeos/síntese química , Glucosídeos/química , Estrutura Molecular , Oxirredução , Estereoisomerismo , Fatores de Tempo
18.
Int J Cancer ; 99(2): 207-12, 2002 May 10.
Artigo em Inglês | MEDLINE | ID: mdl-11979435

RESUMO

There is mounting evidence to suggest that immunization-based strategies can be used to mobilize the human immune system against specific carbohydrate antigens displayed on the surface of cancer cells. Following isolation and identification, such antigens can be administered as conjugate vaccines. The tumor-associated carbohydrate antigen KH-1 is 1 such antigen and may serve as a potential target for immunization against adenocarcinoma. However, a serious impediment to the application of a vaccine-based approach involving this antigen is that its availability from natural sources is severely limited. In order to overcome this limitation, we have developed an efficient total synthesis of this complex glycolipid. We have extended our synthesis to reach a structurally related analog in which the ceramide portion of KH-1 is replaced with an allyl substituent. These synthetic advances have led to the preparation of 2 potential vaccine constructs, each based on the conjugation of the KH-1 nonasaccharide and the carrier protein keyhole limpet hemocyanin (KLH). In 1 construct (KH-1-Et-KLH), the nonasaccharide is conjugated to KLH via a simple ethyl linkage, while in the other (KH-1-MMCCH-KLH), conjugation is mediated by a 4-(4-N-maleimidomethyl)cyclohexane-1-carboxyl hydrazide (MMCCH) cross-linker. We report here the immunological properties of these 2 constructs. Mice were immunized with either of the 2 KH-1-KLH vaccine candidates or the KH-1 ceramide, along with the immunological adjuvant QS-21. Immunization with the ceramide served as a negative control and, as expected, failed to stimulate the production of antibodies against the KH-1 glycolipid. The construct in which the KH-1 nonasaccharide is linked to KLH via a simple alkyl chain stimulated significant quantities of IgM antibodies, whereas the construct linked to KLH by MMCCH induced high titers of both IgM and IgG antibodies. Inhibition data demonstrated that antibodies generated in response to immunization with the KH-1-KLH constructs recognize not only the KH-1 antigen but also the Lewis(y) (Le(y)) antigen, which, from a structural perspective, is similar to the 4 residues located at the non-reducing end of the KH-1 nonasaccharide. Thus, the KH-1-KLH constructs elicit an immune response that successfully targets 2 adenocarcinoma markers. As assessed by FACS analysis, the antibodies raised were strongly reactive with the KH-1/Le(y) positive cell line MCF-7 but not with KH-1 and Le(y) negative melanoma cell lines. Based on the results of our study, a KH-1-KLH plus QS-21 vaccine is being prepared for clinical evaluation.


Assuntos
Adenocarcinoma/imunologia , Formação de Anticorpos , Antígenos Glicosídicos Associados a Tumores/imunologia , Vacinas Anticâncer/síntese química , Antígenos do Grupo Sanguíneo de Lewis/imunologia , Adenocarcinoma/prevenção & controle , Adjuvantes Imunológicos , Animais , Especificidade de Anticorpos , Antígenos Glicosídicos Associados a Tumores/química , Vacinas Anticâncer/imunologia , Configuração de Carboidratos , Sequência de Carboidratos , Ceramidas/química , Ceramidas/imunologia , Reagentes de Ligações Cruzadas , Feminino , Citometria de Fluxo , Hemocianinas/imunologia , Imunização , Imunoglobulina G/biossíntese , Imunoglobulina M/biossíntese , Camundongos , Dados de Sequência Molecular , Oligossacarídeos/química , Oligossacarídeos/imunologia , Saponinas/imunologia
19.
Carbohydr Res ; 337(6): 565-8, 2002 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-11890895

RESUMO

The structure of tetra-O-(tert-butyldimethylsilyl)-D-glucono-1,4-lactone made by the silylation of D-glucono-1,5-lactone has been confirmed by single-crystal X-ray analysis.


Assuntos
Gluconatos/química , Silicones/química , Configuração de Carboidratos , Cristalografia por Raios X/métodos , Lactonas , Modelos Moleculares , Difração de Raios X/métodos
20.
J Org Chem ; 61(2): 455-458, 1996 Jan 26.
Artigo em Inglês | MEDLINE | ID: mdl-11666960

RESUMO

Optically pure enone 9c, available in three steps from known 6-deoxy D-galactal derivative 7b, reacts with cyanophthalide 6 to directly afford the natural product (-)-hongconin (1), a compound from traditional Chinese medicine recently shown to exhibit antianginal activity. The enantiomer of 1 and its (+)-cis-diastereomer were also synthesized in a parallel fashion from the L-sugar counterpart. The use of C-glycoside Michael acceptors, as opposed to their O-glycoside counterparts, represents a potentially useful simplification of phthalide annulation methodology in synthesizing numerous other such optically pure isochromanquinoids, since it obviates the inconvenience of additional steps late in the synthetic scheme associated with reductive manipulation of a remaining acetal moiety into the desired pyran ring substituent.

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